docs: def default_is_local(hadoop_conf=None, hadoop_home=None):
      """\
      Is Hadoop configured to use the local file system?
  
      By default, it is. A DFS must be explicitly configured.
      """
      params = pydoop.hadoop_params(hadoop_conf, hadoop_home)
      for k in 'fs.defaultFS', 'fs.default.name':
          if not params.get(k, 'file:').startswith('file:'):
              return False
      return True